A190630 - OEIS

%I #5 Dec 18 2015 18:17:39

%S 1,4,6,8,63,563,10027,209836,6257561,259705792

%N Half the number of n X n symmetric binary matrices with no element equal to a strict majority of its knight-move neighbors

%e Some solutions for n=4 with a(1,1)=0

%e ..0..1..0..0....0..0..1..0....0..0..1..1....0..1..0..0....0..0..1..1

%e ..1..0..1..0....0..1..1..1....0..0..1..1....1..1..1..0....0..0..1..1

%e ..0..1..1..1....1..1..1..0....1..1..0..0....0..1..1..1....1..1..1..0

%e ..0..0..1..0....0..1..0..0....1..1..0..0....0..0..1..0....1..1..0..0

%K nonn

%O 1,2

%A _R. H. Hardin_ May 14 2011